Blasting cap packages



Feb- 13, w58 H. J. FRAzER BLASTING CAP PACKAGES Filed Jan. 25, 1956 /A//f/yrme #n Prix d fwzff u MM5/f? Wfl/sys,

FIGS.

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BLASTINGY CAP PACKAGES Harvey J. Frazer, Alton, Ill., assignor to Olin Mathieson Chemical Corporation, East Alton, Ill., a corporation of Virginia Application January 23,1956, Serial No. 560,506 3 Claims. (Cl. 102-28) This invention relates generally to a prepared package including electric blasting caps, and particularly to a package wherein the lead wires for the blasting. cap constitute a part of the protective enclosure. This application is a continuation-in-part of my4 prior copending application Serial No. 169,325, filed June 2l, `1950, now abandoned.

. A blasting cap package of the character to whichr the present invention relates is disclosed in United States Patent No. 1,698,962. InV accordance with that patent, an electric blasting cap having lead wires is packaged so that` the body of the cap, which contains a highly explosive and dangerous mixture, is seated within a tube, about the exterior of which the lead wires from the blasting cap are coiled to vnot only atrd protection of the cap, but to provide the lead wires in a condition which will reduce the hazard of handling and placing the cap.

In the patent aforesaid,` the ends of the lead 'wires outwardly of the coil are connected to the tube upon which the wire is coiled byV drawing the wire through .a slot situated at one end of the tube. While the` arrangement disclosed in said patent was used extensively and with eminent success in connection with electric` blasting caps having lead wires which were insulated with textile, and which were of relatively soft wire, the bendingV of which maintained the parts in their desired corelation, such a package has been found wholly inadequate for use withv blasting caps equipped with lead wires which are stift, springy, or provided with slick insulation of the character represented by plastic-insulated wires now in vogue. With lead wires of the characier last mentioned, the package of Patent No. 1,698,962 does not function to retain the wiresin postionwhere they will afford the required protection for the cap,k or to'retain them in such co-relation as to reduce the hazard in handling and application.

It is therefore the object of the present invention to improve upon the package disclosed in the aforesaid patent` and to render it adaptable for use withrlead `wires which are stili, springy, or slick.

Other objects will become apparent to those skilledy in the artr when the following description is. read in connection with the accompanying drawings, in which: Figure 1 is a view in` side elevation of a prepared package constructedin. accordance with the present invention;

Figure 2 is Figure l;

Figure 3 is a sectional view taken along line 3 3 of Figure 1;

Figure 4 is a sectional view taken along line 4-4 of Figure 2; Figure Figure 2;

Figure 6 is an end view corresponding to Figure 2 but showing another embodiment ot the invention;

an Yend viewiot` the/package` shownlA in 5 is a sectional view taken along line 5-5 of 2,823,5i@ Patented Feb. 18, i958 vice Figure 7 is a sectional view taken along line 7-7 ot Figure 6;

Figure 8 is a sectional view takenv along line 8-8 of Figure 6'; and

Figure 9 is a view in side elevation of a further moditication ofthe invention, part ofthe coiled wire broken away to reveal the relationship of the parts.

The present invention makes use of the essential features of theV prepared package disclosed in Patent No. 1,698,962l in that an electric blastingV cap having a: shell 1, which contains a charge of high explosive and is provided withua pair of lead wires 2,. is packed within a tube 4 oifpaper, cardboard, or other suitable material. The lead wires are coiled about the exterior of the tube 4 andviinally the uncoiled portions at opposite ends of the pair of wires are drawn through a slot 5 at one end of the tube.

The present invention contemplates that at least one, and preferably.l both, `of the slots, through which the uncoiled port-ionsof the leadl wires are drawn, be provided with: an olset portion of suicient size to accommodate the cross-section-of the pair of lead wires, and that the mouth of' the olfset portion where it connects with the Vmain portionv ofthe slot be obstructed by a pass of uncoiledv portion of Ythelead wires,` so as to retain the wiresoccupying theoiset portionin position therein with sufficient security to. prevent-their dislodgement under normal handling. The. inherent resilience ofthe material from which the tube is made is,l however, sufficient to permit the pair of lead` wires to be snapped past the obstructing pass (at theA mouth of the oiset portion), so as to be emplaced in, or removed from, the offset portion Without rst removing the pass which obstructs the mouth of the otset.

In. the accompanying drawings, the aforesaid slot in the paper. tube isv J-shaped, having a straight portion 5 and an offset. portion 6 remote from'the mouth of the straight portion4 5 at the end of tube. 4. The area of the offset portion 6 is suiiicientto accommodate the cross-section of the pair of leadl Wires,` as clearly shown in Figure 4.

In the embodiment illustrated in Figures l through 5, the tube 4 is provided withtwo such slots `5y and. 15, arranged diametrically opposite and each having otset portions 6 and 16, respectively, whereas in the embodiment illustrated in Figures 6 through 8, only the slot 15 is provided with an oiset portion 16 so that the opposite slot 5 is straight.

Outwardly of the coiled lead wires 2,k there is an uncoiled portion 7 beyond the coil, and another uncoiled portion 8 between the coil and the blasting cap 1. The lead wires are naked, i. e., stripped ofinsulation for some distance along the uncoiled portion 7`, while the insulationv extends continuously through the coil and to the blasting cap 1 at the opposite end of thev wires;

In preparing the package in accordance with the present invention, the lead wires are coiled upon the tube 4 in two layers, the inner of which terminates in uncoiled portion 7, and the` outer of whichterminates in uncoiled portion 8.y The respectivelayers of. the coillare wound about. thetube 4 in. the: embodiment shown so that the inner layer Vproceedsfrom uncoiled portion17 at thefslotte'd end of tube 4 toward the opposite end, while the outer layer proceeds from the unslotted end of tube 4 toward the slotted end, the winding pitch of the wires being reversed at the unslotted end of tube 4. As shown, the uncoiled portion 7 approaches slot 15 from the straight side thereof, while the uncoiled portion 8 approaches slot 5 from the side of oiiset 6. Accordingly, in preparing the package, the uncoiled portion 7 is drawn through the opposite slots 5 and 15, and seated Iin the offset 6 of slot 5,

which is the nearest slot (lengthwise of thewres) to'the extremity of uncoiled portion 7. Likewise, the uncoiled portion 8 is drawn first through slot 5, entering past the loffset 6 where it reposes adjacent the mouth of the offset 6 which already contains the uncoiled portion 7, ,a,n d thus substantially obstructs the mouth of the offset 6 'and prevents accidental dislodgment of 'the uncoiled portion 7 from said offset. The uncoiled portion 8 is thence drawn through the opposite slot 15, 'snapped past the uncoiled portion 7 (which already occupies said slot 15 at a position adjacent the mouth of its offset 16), and snapped into'position in said offset 16VIV Thus the respective passes of lead wire in front of the mouths'of the respective offsets effectually retain the uncoiled portions 7" and 8 in one of the offsets 6 and 16. j o.

When it is desired to 4place theblasting cap, the shell 1 is removed from within tube 4 and the uncoiled portion 8 of the lead wires snapped out of the offset 16 which it occupies, and out'of the opposite slot 5, -thus clearing the mouth of the opposite offset for ready uncoiled portion 7. v i

In the embodiment shown in Figures-S. the structure is precisely the same as described above in connection release of the with the other figures, except that but one of the slots is provided with an offset portion. In the embodiment shown, slot 15 is provided with an offset 16, but slot 5 is not provided with any such offset. ln this arrangement, only the outermost of the uncoiled portions is drawn into an offset. For example, if,`as shown, the uncoiled portion 8 is drawn into slots 5 and 15 after uncoiled portion 7 has been positioned therein. uncoiled portion 8 will overlie uncoiled portion 7 within slot 5,

and thus when uncoiled portion 8 is snapped into offset 16 and retained therein by the part of uncoiled portion 7 which occupies slot 15 adjacent the mouth of offset 16, uncoiled portion 7 cannot be released from slot 5 as long as uncoiled portion 8 reposes in slot 5 between uncoiled portion 7 and the vmouth of Yslot 5. Consequently, uncoiled portion 8 must be released from offset 16 and removed from slot 5 before uncoiled portion 7 is released.

When it is desired to place the blasting cap from the packageshown in Figures 6 through 8, the operations are precisely the same as before.

If desired, the uncoiled portion 7 in either embodiment may be disposed adjacent the outer Wall of tube 4 before the inner layer of coil is wound thereon, and, in that event, the naked-extremities of uncoiled portion 7 are protected from external forces by the coil itself, as shown in Figure 9. This feature of the invention is applicable regardlessof whether one or both of the slots is provided with the offset portion, except in those rare cases where, in practice, it is desired to make the electrical connection of the uncoiled portion 7 prior to the placement of the cap.

While in the accompanying drawings, the slot in the tube 4 for accommodation of the lead wires is shown as J-shaped, it will be understood that the slot may assume other forms, as, for example, an L-shape, a T-shape, or a C-shape, so long as an offset portion is provided for the reception of an uncoiled portion, and the offset portion is obstructed by a pass of the other uncoiled portionof the lead wires. In any such case, the lead wires are securely anchored against accidental displacement, yet the in- .herent resilience of the paperboard tube 4 permits the lead wires seated in the'offset portion tobe snapped by the pass of lead wire which obstructs its removal.

From the foregoing description, those skilled in the art should readily understand that the invention accomplishcs its objects and provides a substantially improved packaged detonator. While one complete embodiment 5 of the invention has been disclosed in detail and modifications indicated, it is not to be understood that the invention is limited to the details of the disclosure, but that such modifications andvvariations thereof as do not depart from the spirit of the invention are contemplated 10 by and within the vscope of the .appended claims.

Having thus 'described the invention, what is Aclaimed and desired to be secured by Letters Patent is: Y

1. In a prepared package wherein an electric blasting cap is Vcontainedwithir a tube'V having a pair of diametrically opposite s lo'ts at one end, and the lead wires are wound about the exterior of the tube to form a coil with an uncoiled portion at each end of the coil, both uncoiled portionsextending frornthe coil at the slotted end of said tube; thre improvement which comprises, said `slots each having a straight portion .openat the end of the tube and an offset portionY connecting with the straight portion at a point remote fromthe mouth of the straight portion, said offset portions Ybeing diametrically opposed and on opposite sides of a plane through the straight portions of said slots,one ofthe,uncoiledrportions of lead wires, immediately as ,it leaves the coil, being 1disposed within the straight portion of one of the slots athwart the mouth of the offset portion thereof andV extendingacross said tube, and 4seating withinrthe offset portion of the opposite slot,the uncoi led portion atV the opposite end Vof saidlead Ywires, immediatelyasV i't'leaves the coil, being disposed lwithin theF Ystraigheportion of said opposite slot athwart the mouth of thefo'ffset portion thereof and extending across said tube, and seating within the offset portion of vthe first mentioned one'of said slots.

2. In a prepared Apackage wherein an electric blasting cap is contained within a tube having a pair of diametrically opposite slots atfo'ne'end, and the lead wires are wound about theexterior of the-tube to form a coil with 40 'an uncoiled portion at each end of the coil, both uncoiled portions extending from the Vcoil at the slotted end of said tube; 'the improvementwhich" comprises, said slots each lhaving a straight portion open at the end of the tube and 'at least onevof 'saidf slots having an offset portion con- Fnecting with the straight portion at -a point remote from jthernouth ofthe staightportion, onef ofthe uncoiled portions 'of said'le'ad wires, immediately asit leaves the coil, beingdisp'o'se'd'within-thev straight portion of one of the said slots-athwart.',the'mouth of the offset portion "thereof, extending-across said-A tube, and disposed within the opposite slQt,-'-tl 1`e` otherfof' said uncoiled portions of said lead wire`s,iir 1mediatelyfas1 it leaves" the coil, being vdisposed within the straight portion of said opposite slot and across sadtube, and Yseating within the offset portion of the first mentioned oneof said slots. Y 3. The package @of claim 2`wherein a part of the un coiled portion of lead wires which are athwart the mouth of the offset in Aone of said slots is disposed between said tube and said coil.

RefereneesfCited in the file of this patent uNrrED STATES PATENTS 822060. Lawler; May 29, 1906 975,205 Boom ,Now s, |910 

